Photoshop_User_February_2017

› ›

photoshop user

› february 2017

068

LUMINANCE SHARPENING

You can refine a sharpening filter effect by applying it to the

luminance information only. This can be done by converting

the image from RGB to Lab Color under the Image>Mode

menu, selecting the Lightness channel in the Channels panel

(Window>Channels) and then applying the sharpening effect.

An alternative way is to keep the image in RGB mode,

apply the sharpening effect, choose Edit>Fade, and select

Luminosity from the blend Mode drop-down menu. The

effect is near enough identical to sharpening the Lab Color

mode Lightness channel, with the benefit that you don’t have

to change color modes (which may not always be possible

DEPTH-OF-FIELD SHARPENING

Where sharpening problems are due to fall-

off in focus over a critical area of an image,

it’s best to apply localized sharpening to make

those areas appear to be more in focus. In

these situations, a good sharpening method

to apply is the High Pass sharpening tech-

nique, where the High Pass filter is used to

create halos that build up the edge contrast.

This can produce a strong sharpening effect,

so it’s best to create the sharpening on a sepa-

rate layer, add a layer mask filled with black

to hide the effect, and then paint on the layer

mask with white to reveal the sharpening on

just those areas that need it. The following

steps are a little complex, so I recommend you

record these as a Photoshop action.

Step One: In this photograph, the foreground was sharply

in focus, but there was a noticeable fall-off in focus toward

the distance. The first step was to make a duplicate of the

Background layer by pressing Command-J (PC: Ctrl-J).

Step Two: I then double-clicked the layer thumbnail of the

Background copy to open the Layer Style Blending Options.

I set the Blend mode to Overlay and reduced the layer Opac-

ity to 50%. I then adjusted the Blend If sliders at the bottom

to ensure the sharpening effect was limited to the midtone

areas only and the extreme shadows and highlights were

protected. To adjust the sliders, hold down the Option

(PC: Alt) key to split the tone sliders into two so there will

be a gradual transition between the two slider halves.

Click OK to apply these Layer Style changes. Changing the

blend mode to Overlay made the image look quite con-

trasty, but this was only temporary.

with some layered images). The Fade command also lets you

adjust the Opacity so you can apply a sharpening effect and

then fade the Opacity to make the sharpening less intense.